Peripheral devices to a computer are well known in the art. One prior art peripheral device employs magnetic medium as the storage medium. This is evidenced by hard disk drives and floppy disk drives. Hard disk drives can be erased and programmed many times. In addition, they can store a large capacity. Another type of peripheral storage device using solid state memory is the Read Only Memory (ROM). ROM's can be programmable once and read only. ROM devices have the advantage that they consume less power and have faster access time. However, unlike magnetic medium, they cannot be erased and programmed repeatedly.
More recently, as scale of integration has increased, floating gate solid state memory devices have been suggested as being useable in a peripheral storage device. Floating gate memory devices have the advantage that they can be programmed and erased, electrically, thereby, exhibiting the advantages of ROM memory, i.e., low power consumption and faster access, along with the write ability of magnetic medium. In addition, as integrated circuit fabrication scale increases, greater density can be achieved. However, one problem of using the floating gate solid state memory device is that the chip must be virtually defect free. Since the price of each memory chip is dependent upon its yield (the inverse of defect), more stringent requirement of defect free means low yield and high price per chip.
In anticipation of solid state memory storage devices proliferating, a standard, PCMCIA (Personal Computer Memory Card International Association), has been adopted to set the electrical and mechanical interface requirements between a solid state storage peripheral device and a computer system.
In U.S. application Ser. No. 07/977,697, filed on Nov. 13, 1992, a solid state peripheral storage device is disclosed. The solid state peripheral storage device disclosed in that application uses a map ROM which converts the received Logical Sector Number address from a computer and translates them into a Physical Sector Number which is an address to a solid state memory array where the electrically erasable data is stored.